Their supporters call them heroes. The Japanese government calls them terrorists.
Now the United States' largest federal court has declared them pirates.
In doing so, the 9th US Circuit Court of Appeals castigated Paul Watson and members of the Sea Shepherd Conservation Society he founded for the tactics used in their relentless campaign to disrupt the annual whale hunt off the dangerous waters of Antarctica.
"You don't need a peg leg or an eye patch," Chief Judge Alex Kozinski wrote for the unanimous three-judge panel.
"When you ram ships; hurl glass containers of acid; drag metal-reinforced ropes in the water to damage propellers and rudders; launch smoke bombs and flares with hooks; and point high-powered lasers at other ships, you are, without a doubt, a pirate, no matter how high-minded you believe your purpose to be."
The same court in December ordered the organization to keep its ships at least 457 metres from Japanese whalers. The whalers have since accused the protesters of violating that order at least twice this month.
The ruling overturned a Seattle trial judge's decision siding with the protesters and tossing out a lawsuit filed by a group of Japanese whalers seeking a court-ordered halt to the aggressive tactics, many of which were broadcast on the Animal Planet reality television show Whale Wars.
US District Judge Richard Jones had sided with Sea Shepherd on several grounds in tossing out the whalers' piracy accusations and refusing to prohibit the conservation group's protests.
He determined the protesters' tactics were nonviolent because they targeted equipment and ships rather than people.
The judge also said the whalers were violating an Australian court order banning the hunt and so were precluded from pursuing their lawsuit in the United States.
The appeals court called Jones' ruling "off base" and took the rare step of ordering the case transferred to another Seattle judge to comply with its ruling.
The appeals court said Jones had misinterpreted the Australian ruling, which didn't address the protesters' actions.
"The district judge's numerous, serious and obvious errors identified in our opinion raise doubts as to whether he will be perceived as impartial in presiding over this high-profile case," Kozinski wrote.
Charles Moure, an attorney representing Sea Shepherd, said he would ask an 11-judge panel of the 9th Circuit to reconsider the ruling, including Jones' removal from the case.
"They are killing whales in violation of an Australian court order," Moure said.
TIT-FOR-TAT AT SEA
Sea Shepherd ships have clashed violently with Japanese whalers this week, with both sides accusing the other of being in the wrong.
Yesterday Japan claimed the activists were trying to sabotage their refuelling operations as Sea Shepherd insisted the Japanese wre using their large factory ship Nisshin Maru to "ram" the smaller protester ships.
So far no one has been hurt in the at-times violent clashes, which yesterday saw ships damaged, and also feature on Animal Planet's documentary-reality television series Whale War.
Both sides are producing video clips to support their claims.
What is striking however is that the clashes are taking place on a stretch of ocean that also has icebergs and is about 4000 kilometres away from any help.
Both sides have been clashing since 2008 and this time the Japanese fleet has a tanker, Sun Laurel, with its fleet of whale chasers and factory ship.
- AP and Fairfax NZ